As there are many different types of contact lenses, there are also many different wearing and replacement schedules. Each lens is designed for a specific length of wear.
For daily contact lenses, two weekly and monthly contact lenses, the times frames for replacing the lenses are simple and straightforward.
Daily disposable lenses should be thrown away after each single day of use. Two weekly and monthly disposable lenses however, have a longer wear period. These reusable lenses must be stored in fresh solution overnight and disposed of every two weeks and every month, respectively.
You can now get silicone hydrogel lenses for all these different types of contact lenses. Silicone hydrogel lenses are popular as they reduce your chances of getting hypoxia from lens wear
Gas permeable lenses are more resistant to lens deposits. Therefore, they don't need to be replaced as often as silicone hydrogel lenses. They can last a year or more before they need to be replaced, provided that they are stored in fresh solution and cleaned effectively.
You can also get soft contact lenses that last for a year. The problem with these lenses is that they pose a higher risk of getting a bacterial eye infection known as Microbial Keratitis.
What are extended wear contact lenses?
Extended wear contact lenses provide a bit more flexibility for the contact lens wearer in terms of the length of time they are worn for and how often they're replaced.
Some two weekly and monthly contact lenses offer the option to wear them continuously for a reduced amount of time. These are extended wear contact lenses and, if prescribed by your optician, they will allow you to enjoy the freedom of wearing your contacts day and night. This will save you the trouble of cleaning and storing them every night.
It’s important to remember that this reduces the life of your lens. Therefore, you’ll only be able to enjoy the added convenience of continuous wear for a limited amount of time. This is typically up to seven days and seven nights with each pair of lenses.
How many hours a day should you wear contact lenses?
It’s always best to speak with your optician regarding how you wear your contact lenses and how long you should wear them for. However, general practice goes that you shouldn’t wear most contact lenses for longer than 10-12 hours a day.
The problems posed by wearing your contact lenses for too long include discomfort, drying of the eyes, redness of the eyes and increased chances of an eye infection. If you experience any of these problems, you should consult an eye care professional immediately.
What happens if I don't change my contact lenses every month?
Failing to replace your lenses when required can cause your cornea to swell and lead to corneal abrasion, dry eyes, red eyes and an overgrowth of blood vessels which in turn can cause irreparable damage to your cornea. If you wear yearly contact lenses, then you don’t need to worry about replacing them every month, so long as they are cleaned and stored effectively.